Question

ab –mn +an –bm = ?

(i) (a-b) (m-n)

(ii) (a-m) (b+n)

(iii) (a-n) (m+b)

(iv) (m-a) (n-b)

Answer 1

(ii) (a-m) (b+n)

let us rearrange the terms and take a and m as a the common factor we get,

ab –mn +an –bm 

= ab + an –mn – bm

= a(b+n) –m(b+n)

= (b+n) (a-m)